From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1E4A026E6F4; Fri, 21 Nov 2025 13:22:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763731339; cv=none; b=r1XWMKlwMYU6dyUSdTEWGWaojd30X9H9mdsKo7w0cDuNjZJpYaAA9nr+Lv1fBO/oBykNcrGxVONczmEAY+9/Sop9v/WOdnHiX7WGGkUJxvKvuUDz38skP+wPYqSZh1fQl3QmLGPvDZ/5RSO+dv2em9SYOl4Y2eZGZSB7n5LynBg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763731339; c=relaxed/simple; bh=keLyYB07+nk8ANsooJwPD3GXYNdTblpPD6vw1hMXNo0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=P4tE+S7hVnU/UD/Qz1glszZDPhZaUxP6aq1k7ngQVt/4S3bSDExdb4TOHzgDLIe3ES61WJAV0mrTxu4XNVNzb9ui7047tx8VbaJ8FFzI4Dt2SGlktTa00tqUvkyELHOlVT3zbF+k8NRzm7pQDPzXJlrGLqxJ0bpC32FFQsnLtDc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Eac3rKsz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Eac3rKsz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 96CCCC4CEF1; Fri, 21 Nov 2025 13:22:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1763731339; bh=keLyYB07+nk8ANsooJwPD3GXYNdTblpPD6vw1hMXNo0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Eac3rKsz+WvZOhZgAYOA7KRekbq82ugY8J6GM+ZA7faammU+P+YDOnarLUSni1ibZ w8M+y0pvjwyD1V6OJxxHa3GhZr2zinI8MLzVF6GTzDFfnU+I5TWsGk2D60bqIH9lD1 Wo6d0EvtL+LbE+bHtR6WuLTTx1EBF6nJ6yWWCEFU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Liupu Wang , Tianyang Zhang Subject: [PATCH 6.17 173/247] LoongArch: Let {pte,pmd}_modify() record the status of _PAGE_DIRTY Date: Fri, 21 Nov 2025 14:12:00 +0100 Message-ID: <20251121130200.929507298@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251121130154.587656062@linuxfoundation.org> References: <20251121130154.587656062@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tianyang Zhang commit a073d637c8cfbfbab39b7272226a3fbf3b887580 upstream. Now if the PTE/PMD is dirty with _PAGE_DIRTY but without _PAGE_MODIFIED, after {pte,pmd}_modify() we lose _PAGE_DIRTY, then {pte,pmd}_dirty() return false and lead to data loss. This can happen in certain scenarios such as HW PTW doesn't set _PAGE_MODIFIED automatically, so here we need _PAGE_MODIFIED to record the dirty status (_PAGE_DIRTY). The new modification involves checking whether the original PTE/PMD has the _PAGE_DIRTY flag. If it exists, the _PAGE_MODIFIED bit is also set, ensuring that the {pte,pmd}_dirty() interface can always return accurate information. Cc: stable@vger.kernel.org Co-developed-by: Liupu Wang Signed-off-by: Liupu Wang Signed-off-by: Tianyang Zhang Signed-off-by: Greg Kroah-Hartman --- arch/loongarch/include/asm/pgtable.h | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/arch/loongarch/include/asm/pgtable.h +++ b/arch/loongarch/include/asm/pgtable.h @@ -424,6 +424,9 @@ static inline unsigned long pte_accessib static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { + if (pte_val(pte) & _PAGE_DIRTY) + pte_val(pte) |= _PAGE_MODIFIED; + return __pte((pte_val(pte) & _PAGE_CHG_MASK) | (pgprot_val(newprot) & ~_PAGE_CHG_MASK)); } @@ -547,9 +550,11 @@ static inline struct page *pmd_page(pmd_ static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) { - pmd_val(pmd) = (pmd_val(pmd) & _HPAGE_CHG_MASK) | - (pgprot_val(newprot) & ~_HPAGE_CHG_MASK); - return pmd; + if (pmd_val(pmd) & _PAGE_DIRTY) + pmd_val(pmd) |= _PAGE_MODIFIED; + + return __pmd((pmd_val(pmd) & _HPAGE_CHG_MASK) | + (pgprot_val(newprot) & ~_HPAGE_CHG_MASK)); } static inline pmd_t pmd_mkinvalid(pmd_t pmd)